[dkd7]

After receiving my Hi-Fi News test LP, I figured I would run the gamut of tests it provides primarily focusing on anti-skate and azimuth. The table is level on all accounts, verified by 2 more levels and this is based on the top of the TT, the platter is also level.

I originally rewired the TT with Blue Jeans  LC-1 and are 5' in length, solder job was perfect. Cart in question is the DL-301 Mk2 running through a Phonomena 2 into a Yamaha CX-1000 pre then a B&K ST-202 and the offset on the amp is +2.0mV on the right and -1.6mV on the left. I also double-checked the gain on the Phonomena and it was the same.

I leveled the tonearm at "0" grams and AS was at "0"...no movement until I dialed in 2-3 on the AS then the arm moved outwards....as it should so at least I know the AS is working. I set the VTF to 1.5g and played the test LP. What raised a brow was the very slight bias towards the left, now with Polk SDA speakers this can be skewed a bit but the headphones verified this. I even swapped the headphones to the opposite ears to verify and indeed, side 2, track 5 for the azimuth test was slightly biased on the left.

One other thing was I had slight buzzing at 1.2-1.5 on the AS and went away at 3..seems high. I checked and rechecked the azimuth by the mirror method, I even used some solid metal cubes, cylinders that are known right angles and I placed them on the platter and the cart is straight. However when I lower the arm the arm kicks outwards slightly and the stylus leans inward, but not too much. When the record is playing the cart stays put and there is practically no deflection, this is at all AS settings and obviously reduced at lower AS settings.

I have the cart set to the Baerwald protractor and I have been considering using the Stevenson or just straight in the headshell at 52MM.

The cantilever is straight and has not been abused in any way. I have been playing it this way for 50-100 hours and just now I have noticed the bias...didn't pay too much attention to it originally as I didn't have the test LP to begin with, the newly acquired Audio Technica ATH50's really resolve this issue more than my old Sony's. I have also been dealing with room acoustics and figured that was also a culprit.

I honestly can't think of anything other than alignment being the cause. Hopefully I disclosed all the pertinent information. I think the cart sounds great but want to be sure everything is correct before I maturely wear the stylus.

[Wayner]

I'm not sure where you set your anti-skating dial at, but it it should match the weight of your VTF. So if your tracking at 1.5 grams, the anti-skate should read 1.5. However, my Technics will not behave properly (using a blank test disc) until the dial reads 2.3.

Why you ask? Because the dials are not accurate. They get you in the ballpark, but they need help, either by visual, or auditory methods.

My advice to anyone setting up a table is to always set the cartridge VTF slightly high to the middle of the recommended range. Vinyl damage occurs with too little tracking force/incorrect anti-skating, in which the stylus is not riding properly in the groove and is actually rattling in the groove, which is what causes record damage. So, for example, if your cartridge VFT recommendation is in a range of say 1.3 to 1.7 grams (1.5 would be in the middle), I would recommend (to start with) a setting of 1.6 grams. Then adjust AS as required.

A few things that affect AS are VTF and alignment type (Stevenson, Baerwald, Lofgren), and azimuth of the cartridge. After all, it is just like a little boat rudder and without any AS, it wants to pull the arm towards the spindle. The whole purpose of anti-skate is to equalize this pressure. The are a few methods used to accomplish this, one uses magnets, another uses springs and yet another uses "dead man" weights.

The best method to set AS is with a blank disc. When AS is set properly, the arm should remain stationary at any point in the usual playing area. The test record will the confirm it.

Improper AS will also affect imaging/soundstage, depth of recording and instrument definition, because information is either being missed or there is lots of tracking distortions.

Wayner

[dkd7]

I'm not sure where you set your anti-skating dial at, but it it should match the weight of your VTF. So if your tracking at 1.5 grams, the anti-skate should read 1.5. However, my Technics will not behave properly (using a blank test disc) until the dial reads 2.3.

On the large blank tracks of the test LP, the arm stays put with the AS at 3, This was also confirmed by the AS tracks of the LP where it showed even sound in both ears. Only problem is I still had slght buzzing but it was equal on both sides. I can get the buzzing to move from right to left by adjusting the AS and it seems to be neutral at 3 with only very seldom buzzes at that setting.

After setting the AS I still have a noticeable bias towards the left and this is the same regardless if the VTF is 1.3-1.6. Could playing the cart for this amount of time possibly wore a slight pattern in the tip influencing the left bias?

[neobop]

On the large blank tracks of the test LP, the arm stays put with the AS at 3, This was also confirmed by the AS tracks of the LP where it showed even sound in both ears. Only problem is I still had slght buzzing but it was equal on both sides. I can get the buzzing to move from right to left by adjusting the AS and it seems to be neutral at 3 with only very seldom buzzes at that setting.

After setting the AS I still have a noticeable bias towards the left and this is the same regardless if the VTF is 1.3-1.6. Could playing the cart for this amount of time possibly wore a slight pattern in the tip influencing the left bias?

Wear pattern?  My 8 ball says unlikely. You could be skewing the cantilever.

"After setting the AS I still have a noticeable bias towards the left and this is the same regardless if the VTF is 1.3-1.6."

Noticeable to ears or eyes or both?  Did you try reversing the leads to verify imbalance?  Reverse at the phono stage to make sure imbalance isn't downstream of the table. Reverse at cart pins to see if it's cart or wires. After step 1, I suggest putting it back to normal to avoid confusion.

It's normal for AS to make an arm go toward the outside when lowering. Even though there's weight on the arm, the stylus isn't holding it in a fixed position.  It's also normal for the alignment to look slightly skewed at beginning of record. At that point it's out of alignment. The first null point encountered will be around 120mm from the spindle.

If describing bias in one direction or another, we need to know if it's the stylus to the left or cart body, when viewed from the front. It sounds like you followed procedures, but I suspect you have too much AS.

I almost forgot, how do you like those M50?

[Wayner]

I also have a hard time with the AS dial set at 3. It's seems like it is just too much. Mine is off, but not that much.

Buzzing can also be caused by incorrect cartridge alignment. The Technics has a spindle to tonearm distance of 215mm (I have no idea where your 52mm comes into play). To set it in a Baerwald alignment, the overhang should be 17.8mm and the 2 null points would be at 65.998 and 120.891 respectively.

If you do not have these perimeters set correctly first, that would explain the more then large grams of force required for the AS. Azimuth can cause this too, but the 1200 does not have this adjustment, tho you can jiggle the headshell one way or another a slight amount.

I suspect your alignment needs to have more fine tuning. I know it's a pain in the ars, but I suspect that your problems will not go away until alignment, azimuth, VTF and AS are all happy.

Wayner

[neobop]

Maybe 52mm is the overhang when using a headshell gauge and stock alignment?

Azimuth and anti-skate are parameters that impact on each other.  You could get an aftermarket headshell with azimuth adjustment.  I don't know if you need it, but something like a Sumiko can be adjusted. Sometimes the orientation of the diamond isn't completely in agreement with the cart body. The cart could look perfectly straight while the tip is at an angle. Denon carts seem to be well made and inspected, in my experience, so I don't know. You should be aware of options. I doubt if the extra weight of such a headshell will be a problem. I had a 304, also with high cu, and it seemed to sound better with an arm around 14g or a little more.

Azimuth problems will make high frequencies drop out of one channel.  Image will tend to be most affected.  You can check with a mono record. Female vocals seem to be especially revealing.
If your cart looks straight I think you can probably fix with anti-skate.  View your cart from the front while playing. You have to make sure you're directly in front and not off to the side. See if the cantilever is close to centered. Check it at different parts of the record. 
Beside buzzing that Wayner mentioned, something like a loose headshell screw could be the culprit. If the problem is more loudness in 1 channel, try reversing the headshell wires and see what happens.

[dkd7]

Noticeable to ears or eyes or both? Both

Did you try reversing the leads to verify imbalance? Not yet, but I will when I return home on Sunday.

Reverse at the phono stage to make sure imbalance isn't downstream of the table. Reverse at cart pins to see if it's cart or wires. After step 1, I suggest putting it back to normal to avoid confusion. That's a great idea and I will definately do so and report back.

If describing bias in one direction or another, we need to know if it's the stylus to the left or cart body, when viewed from the front. When viewed from the front.


I almost forgot, how do you like those M50? I only wanted a sub $100 set, the reviews of the ATH30 agreed that the extra $$ for the 50's were worth it. I haven't heard a nice set of headphones for a long time and I wasn't prepared for how nice these sounded. The Guitar Center had a 4th of July coupon so for $135 I jumped on it.

Yes, I really enjoy them and i'm very surprised at how well the bass comes through and the highs are very clean. They are slightly big, but not bad...I enjoy the critical listening aspect and these deliver. I don't care if i'm at the pool with these on but may seem out of place at the in-laws dinner table 

I don't know how much more you need to spend to better these while keeping a closed-back but I can only imagine them with a dedicated headphone amp..... I can't believe they are only $150 on the high side.

There was a grin on my face for the first 5 min or so I listened to them.

If you do not have these perimeters set correctly first, that would explain the more then large grams of force required for the AS. Azimuth can cause this too, but the 1200 does not have this adjustment, tho you can jiggle the headshell one way or another a slight amount.
Wayner

I'm actually using a LP Gear Zupreme headshell so there is azimuth adjustment. I agree it's definately a pain in the A%& and me being the one to make sure everything is correct, I had no idea a TT setup required such a precise amount of adjustment, and that's putting it lightly. Back in the day I just turned it on and stacked albums on the automatic spindle..lol, but a nice setup is as rewarding as the time you put into it but tenfold at the least.

Sometimes the orientation of the diamond isn't completely in agreement with the cart body. The cart could look perfectly straight while the tip is at an angle. Denon carts seem to be well made and inspected, in my experience, so I don't know.

That could be the case and I am putting faith in Denon to have it straight but in the end, it's me that needs to ensure this.

If everything checks out, I may rig a set of RCA's to check for crosstalk with my DMM for the azimuth.

[neobop]

Looking over your initial post, I'm almost positive you have too much anti-skate and that's it.
The 301II tracks at 1.4g +/- .2,  I seriously doubt if 3 on AS dial is appropriate.  All the symptoms you describe are too much AS.  Before you mess with anything else, try backing off AS to around 1.2 on the dial and see what happens.

Many people who rely on HFN test record for AS, wind up with way too much. Even though you followed directions for equal buzzing, stylus velocity was too high.  The amount of AS is a compromise because skating force varies with stylus position on the record and loudness (stylus velocity).  Check it with your normal music. It's better to have it slightly low than too high. I've found that viewing from the front is very revealing and will get you in the ball park easily.

A DMM isn't much good for azimuth. If in doubt try the mono record. I have a feeling that after your AS is sorted out, you won't feel the need to correct azimuth. 

[cindy_leigh]

I totally agree with backing off the anti-skating force to 1.2, or maybe even slightly less.  One problem with the test record is that skating goes in the direction it does because the friction is in that direction. On the test record, your stylus is on flat vinyl instead of riding in a groove.  The friction there is different from real-life conditions.  That's not to say a test record is useless for judging anti-skating force, but a correct setup would probably tend to ride inward.

[dkd7]

What's the consensus on the Baerwald alignment with the 1200? Has anyone tried it then switched to the stock 52MM or perhaps the Stevenson and thought that the others were noticeably an improvement?

Just looking to isolate another possible culprit. Could be inconjunction with the AS that I may have the alignment off just a smidgen and enough to throw things out of whack.

[neobop]

What's the consensus on the Baerwald alignment with the 1200? Has anyone tried it then switched to the stock 52MM or perhaps the Stevenson and thought that the others were noticeably an improvement?

Just looking to isolate another possible culprit. Could be inconjunction with the AS that I may have the alignment off just a smidgen and enough to throw things out of whack.

Unless you're having problems near the inner grooves, IMO you should stick with a Loefgren alignment. Loefgren A (Baerwald) is optimised for lowest average distortion throughout the record. Loefgren B gives lowest total distortion.  Stevenson has the inner null at the lead out groove, alignment error will be greater at the beginning.  I think you should sort out the AS (or whatever) first, and then consider a different alignment, if so inclined. You might want to check it before you proceed. Severe angular misalignment can cause an audible phase error between channels. This often isn't noticed until corrected.

My recommendation to drop AS to somewhere near 1 on the dial, wasn't suggested as a final setting.  You should see centering in a more correct position or going the other way. I think that will give you a point from which to start. Maybe like Wayner, you'll wind up with a setting in excess of your VTF. However, I don't recommend a blank disk setting.  Hopefully there are no other problems.  From your descriptions, it sounds like you did everything right.

[dkd7]

I went and took some sound measurements with an SPL meter directly in front of the speakers, same position on both since I can't trust my ears for this.

All connected normal         Left 98db    Right 96db

Phono Pre out reversed      Left 97db    Right 96db

TT to Phono pre reversed   Left 96.5db Right 95.5db

IN at preamp reversed       Left 97db    Right 96db   This was to isolate interconnect

TT leads reversed              Left 98db    Right 96db

Changed input location at preamp   1.5db less for each but still left bias


Looks to neutralize the preamp as the culprit, could this just be a bias pot or a capacitor issue....or both?

[neobop]

What happens if you reverse interconnect - pre out to amp in?

[dkd7]

What happens if you reverse interconnect - pre out to amp in?

Are you referring to the direction or signal path, or just left to right?

I did the left to right switch and that is the "Phono pre out reversed"

[neobop]

Right to left - preamp main out to power amp in.
You're measuring SPL at the speakers.  What if left side of your amp is stronger?

Assuming there's no problem with the interconnect, loud channel should switch sides if it's the preamp.  If it does switch sides, reverse the leads at both preamp and power amp to check that it's not the cable. (use red side for left). 

[dkd7]

I swapped the leads at the amp and it's still louder on the left but just over 1db. I changed the leads over from pre to amp, swapped both ends so red was left and white was right on both ends, still about 1db biased to the left.

Thing is, I notice a left bias through the headphones and that's through the preamp.

[neobop]

I don't know.  "They" say that 3dB is the smallest volume change discernible by humans. Maybe that only applies to total volume. Is there a room boundary that could be reinforcing the left channel? What are you using as a source, the test record or a variety?  Perhaps another source like a PC or CD will help sort it out.  BTW, you had 2dB difference, and when you initially swapped sides it was 1dB. This latest test indicates it's your amp or speakers. You've gone this far, maybe you should switch speaker leads so the left side of your amp is driving the right speaker. The only way both headphones and amp can be explained is it's both amp and preamp or amp and headphones?  Oy vey.

What happened with anti-skate?  If you haven't messed with it, I suggest setting where it looks centered, at least for now. Even though these SPL readings seem questionable, I don't doubt you're hearing something.

[phonomac]

Hello there,
 Regarding Baerwald vs Stevenson on the Technics SL1200, I did a fair amount of experimenting, using the alignment comparator on VE and trying various options on the t/t.

  What I ended up with is an overhang 0.5mm greater than spec (ie 52.5mm on the Technics gauge), with the cartridge parallel to the headshell sides. If you plug these numbers into the comparator you will see that you give away a little at the beginning of the side, but are then ahead of the game all the way to the inner grooves. In real life this gives me very clean sound all the way through.

  I don't think that Baerwald vs Stevenson or any other alignment is the cause of your channel mismatch, just responding to your query on alignments.

regards

Angus

[dkd7]

So I printed another Technics/Baerwald protractor and confirmed the rulers were in spec. Took a fair amount of time to ensure I created an exact hole for the spindle. I used the pencil graphite sticks this time to aid in alignment and it appears there was just a slight tilt to the left or outside when viewing from behind.

I understand that these instructions have been spoken and written many times that the alignment must be exact, my question is how off can the measurements be before you run into trouble.

Here's the angle I have when I noticed my problems or basically my current alignment:




This is after I straightned it just a tad:




Outer null point:




Outer radius:




Now the arc trace just starts to move inward after the inner null point, and at the limit of travel for the arm is where it's tracking inside. My question is since I cannot reach the inner "C" point, does the stylus still need to trace the arc after the inner null point?

The stylus is just the slightest bit at the inside edge of the line at the inner null point, but still at the line, granted it started at the center of the line at the outer null point.




This is at the limit of arm movement.



My gut tells me to have it trace the arc perfectly past the inner null point, just want to get an opinion though.

[Wayner]

You are way off. Your outer null is outside of the arc, your inside is inside of the arc. So, you are not following the arc.

W